[ RadSafe ] Please Critique This Reply by Rosalie Bertell

[Rosalie Bertell]

Dear Mr. Marcel Schouwenburg,

 

Thank you for this reference. My source was the Handbook of Health Physics
and Radiological Health, Third Edition, Edited by Bernard Schleien, Lester
A. Slaback, Jr. and Brian Kent Birky, Lippincott Williams and Wilkins,
Philadelphia,1998.  on page 12-13, it is stated:

"The model is intended for use with aerosol with AMADs between 0.2 and 10
micron and with geometric standard deviation less than 4.5. Provisional
estimates of deposition further extending the size range are given in the
dashed lines of Figure12.3. ... The model does not apply to aerosols with
AMADs less than 01. micron. (Courtesy ICRP from Publication  54, 1987)".

 

Could you please explain why ICRP 66 (1994) changed this limit. This should
have been promulgated by 1998. My understanding is that when particles are
of AMADs less than 0.1 micron they behave like a gas. They freely enter
through the cell walls, the lung-blood barrier, the blood brain barrier and
cross the placenta. The other major problem is that are too small for the
kidney filter. Was this decision made after the first Gulf War for some
reason?

 

Dr. Rosalie Bertell

 

-----Original Message-----
From: Marcel Schouwenburg [mailto:m.schouwenburg at tudelft.nl] 
Sent: Wednesday, February 21, 2007 6:12 AM
To: Roger Helbig
Cc: radsafelist; Rosalie Bertell
Subject: Re: [ RadSafe ] Please Critique This Reply by Rosalie Bertell

 

Daer Mrs/Ms Bertelli,

The ICRP Respiratory Tract Model can be apllied to particles with a diameter
< 0.1 micron. For this purpose the model describes a.o. fractional
deposition in various compartments of the respiratory tract for particles
down to a an Activity Median Thermodynamic Diameter, AMTD (to be used in
stead of the AMAD because of the small particle size) of 0.001 micron. So,
the model can also be used for particles in a DU aerosol with a size between
0.001 micron and 0.1 micron. 

Reference
ICRP-66 (1994), Human Respiratory Tract Model for Radiological Protection.
ICRP-Publication 66, Annals of the ICRP 24(1-3), Elsevier Science LTD,
Oxford, pp. 49-54.

With kind regards,

Marcel Schouwenburg
Head / Lecturer Training Centre Delft, Health Physicist, expert level 2
RadSafe Moderator & Listowner
National Centre for Radiation Protection (Dutch abbr. NCSV)

Delft University of Technology
Faculty of Applied Sciences / Reactor Institute Delft
Mekelweg 15
NL - 2629 JB  DELFT
The Netherlands
T: +31 (0)15 27 86575
F: +31 (0)15 27 81717
M: +31 (0)6 419 83 145
E: m.schouwenburg at tudelft.nl <mailto:m.schouwenburg at iri.tudelft.nl> 



Roger Helbig wrote: 

----- Original Message ----- 
From: "Rosalie Bertell"  <mailto:rosaliebertell at greynun.org>
<rosaliebertell at greynun.org>
To: "'Roger Helbig'"  <mailto:rhelbig at california.com>
<rhelbig at california.com>
Sent: Tuesday, February 20, 2007 8:45 AM
Subject: RE: Nichols Publish the Truth??????
 
 
Dear Roger,
 
My guess is that you are sending the estimates by the physicists who use the
ICRP Respiratory Model methodology. This is only valid down to particles of
aerodynamic diameter of
0.1 micro. DU aerosol has been shown to coalesce into particles of
aerodynamic diameter between 0.001 and 0.1 micron (nano particles).
Therefore they miss some of the most serious effects.
 
Dr. Rosalie Bertell.
 
 
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